The present invention relates to a new and improved construction of apparatus for winding filamentary material, such as specifically a thread or yarn--hereinafter simply usually referred to as a thread--upon a rotatable conical bobbin tube so as to form a bobbin package.
Genrally speaking, the winding apparatus of the present development contains a rotatable friction drive drum for winding the thread onto the rotatable conical bobbin tube into the bobbin package. This friction drive drum comprises a plurality of substantially cylindrical rotational elements which are arranged upon a common driving or drive shaft and which contact the bobbin tube or the bobbin package, respectively, along a generatrix. With this arrangement, during the winding operation, the bobbin package and the friction drive drum roll upon one another.
For winding a thread or yarn into a bobbin package the use of conical bobbin tubes, i.e. substantially truncated cone-shaped tubes, is desirable in many instances. The rotation of the bobbin tubes which is required for producing the bobbin package, as a general rule, is generated through the use of a substantially cylindrical friction drive drum. This friction drive drum contacts the bobbin tube or the thread material which has already been wound upon the bobbin tube, as the case may be, along a generatrix. With this arrangement, the bobbin tube or the bobbin package, as the case may be, is frictionally entrained by the friction drive drum. Since the bobbin tube is of conical shape and the friction drive drum is of cylindrical shape, it will be appreciated that the surface speeds of these rotating bodies along the previously mentioned generatrix or contact line do not coincide with one another. Specifically, at the locations or points of relatively large diameter of the bobbin tube the jacket or outer surface of the bobbin tube moves at a greater circumferential speed, and at the points or locations of relatively small diameter of the bobbin tube the jacket or outer surface of the bobbin tube moves at a slower circumferential speed, than the surface of the friction drive drum. Thus, the surfaces which are in mutual contact with one another at such locations tend to rub or abrade against one another, something which is quite undesirable because there is impaired during such scuffing action the quality of the wound-up thread.
In German Patent Publication No. 2,228,488 there is disclosed an apparatus wherein, for the purpose of maintaining the winding speed and the uniformity of the thread tension at a distribution drum, there is maintained small the contact surface of the distribution drum at the bobbin package. In this way there can be considerably reduced the abrasion or scuffing of the surface of the bobbin package and the distribution drum. However, when using a small contacting surface the frictional engagement or coupling between the bobbin package and the cylindrical distribution drum, and therefore, also the entrainment of the bobbin package, has proven to be insufficient.
In Russian Pat. No. 494,868 there has been disclosed the use of a drive drum composed of a plurality of elements for winding a bobbin package which is driven by a shaft rotating at a constant speed. Two elements of the drive drum can be selectively connected, as desired, by a coupling with the shaft in order to transmit the drive, so as to control the winding speed and to obtain a uniform density of the windings of the wound bobbin package. Yet, this Russian patent is not concerned at all with the presence of surfaces which slide and abrade against one another.